office



Bitocess: Foe: TREATMENT: oF-v CASHEVW NUTSHEIJLtLIQUIDANILTI-IE-BESULTING;

t. PRODUCE:

Roland-E: Kremers' SummitfN; J; assignor'to j .Genera'lFoods'corporation;'Hoboken, J;-, 3?."

corporation of Delaware ive Drawing"; ApplicatiomMayA; [1942,- H

'The'present'invention relateslto the treatment of cashew nutshellliquidf and more: particularly to" an improved" method of treatingthe liquid 1 to convertitintoaplastic'producti The principal -object'ofthe invention isto' pro- Vide a methodofconvertingcashew nutshell"liquid of relatively'high anacardic acidf content into a plastic formwhich iadaptedtwbb packed in -inexpensive-papersacksor other suitablecontainer's "and which-'may bestorewandfor ship fidwithout'undergoing-anv substantialchange and which may'be"safely-"handled during shipment l :i'i:v- J Han -41 v i a H,

Another objectofthe "inventionis toprevem; contaminationof cashew nutshellliquidwf fhig'h anacardicacidcontent as a resu l-tfof the corrosion which would otherwisemccur if the liquid is shipped in metalliccontainers, by converting the liquidfinto aiplastic 'formiwhich'is'adapteditoibe shipped'in paper or'otheri suitablenon-metallic containersor in metallic containers without be? ing'subjectto' the aforesaidcontamination'by corrosion f; j

I 'A-"further objectfoftthe inventionis;toiprevent the injury ofhandlers ofcashew nut shellili'quid during shipment thereof byconverting the toxicvesicantiliquidf into 'a non toxi'c; plastictstateni'r whichit-maybe-safely handled-p i A still further objectof-theinventiorris-tocom vertcashew nut shell *liquid into' at'plastic'productby reacting said liquidwith -asuffioientamountfof a suitable alkalinecompoundand from whicli the cashew nut shellvliquid. may be laterrecovered in approximately its original; condition vbysuitabletreatment'of'the'solidproduct! Another object of theinvention'iistd provide amethod' of'recovering'cashew' nutshell liquidfrom a plastic" reaction product of cashew *nut' shell liquidand asuitable alkaline cormeourrcl;

The necessity for improving; the commercial methods for the storage-andshipment of cashew nutshell liquid arises from-thefact-tliat--tl'le-hig-h qualityliquid-- produced -by'=--moclerrrextraction methods, and havin an 1 anacardi-c acid content of"fromto 65% or 70%, uniortunately is liable toundergo-spontaneousdecomposition witlr the evolution of C02,? thusbuilding-up an" execs: I

sive pressure-in= the drums' ine; which the liquid- 1s shipped: Thistends-- to cause loss of the liquid due to opening of the seams andsometimes burst ing of thedrmns -'ln;wh'ich the liquid isstored andtransported; and also may poison 1 persons-'iwho Y come incontact with:the toxic-, vesicatingz oil through handling theleaky drumsa Eurtheremore; the avail able supply of metals' at-"time'ssbe comes limited.

(o1. aco-+521) 1 Now; in-accordanceawith thepresent'inventiom lhhasabeenfoundxthat theabove-mentionedzEdif culties may be obviated and thatcashewnut shell liquidi'of high anacardic acid content, say; of at least40% may be converted; into a plasticwnrod not imwhich: the anaca-rdic.acid.- is stabilized against decomposition by reacting it withasufficient-amount ottaneoxide onhydroxidevotaisuitable metal, and; that the:plastic: product: thus; produced 1 may be safely-1 stored; and shippeddnnon-;metallig-:; containers, such: as .paper bags,-;;andthat;thmcashewnutashell liquid,-ma-y lbe zrecow erectin apprommatelygits;original condition by; wt nerthep ic p d w hw u ta le amount of a;dilute acid; The eashewnutpshellhydroxide, or it'mavbe convertedby-theaddition of; ia sm all amount: of Water-into. 1 a. water in-oil emulsionwhichr may then benreacted. with the oxide EORhYdI'OXldG r i V I Forpurposespt illustration, but .notvby wawofi limitation; thisainventionis,hereinafter described as. practiced: byreacting hydratcd lime withcashew i, nut shell liquid.v Generallyit has been as foundthat-the'slaked lime'used for. the sol-idifica tion; of. cashewtnut,shell liquid-should not contain a high percentage'of magnesiumoxide-or-hydr'ox ider i' fla desirable product is to ,be obtained t Forexample, ini mostr-instances-ethe. amount of mag nesia associated, withthe' lime willnot; exceed about.-l5v%. In general, the lowerthermaghesia content in f the lime, the. better, will ,be, thiPhYSif calpropertiesgof the. product; It willl.iof, course} understood,,thatln.placer'oflhydrated lime- 1111: slakedtlime or oxides andthydroxidesof .theiother allialineearth metals, suchla'srthe oxides.,andrliydroxidesfl of bariumfland. strontium utilizecL,

In tpracticinggthe'jpresent invention, a sufficient quantityoi lime isaddedeither to thetcashew nut. shell liquid of highlanacardic ,acidcontent I.or\ .to. anemu1sion thereoiitoeform a plastic; massfwh'ichsubsequently hardense Thesa'mountlo'f glime em,

ploi'ed isinexcess ofithat theoretically; required 45 ten react withthetanacardic racicl ofgth cashewv nutlshell liquid toiom thegneutral-salt andlthe.

excess -present may bel-variect to obtain; a, plastic productriof; thedesired'characteristics. For ex,-

ample; in they. caseeofi at liquid; containing; from 6 to;anacardiczacidgqthe mostsdesir'ablej properties; ofi the, reaction:-product: areeobtained' with afiamountaoi ilirne included .the range of:fronr about 12f%" to about-% by weight of the 5,5 turewill rem-ain too'fluid "in" tropical regions ror liquid may be treateddirectly-.'with,thei=oxide,;orv safe handling, While if more than 25% oflime is utilized, the cost of materials and the tendency of the mixtureto solidify too rapidly will become serious factors.

It has been found that the addition of a small,

amount of water to the cashew nut shell liquid to form a water-in-oilemulsion prevents a premature setting of the mixture when lime is addedto the liquid and provides a 'productwhich pours easily and is readilyhandled. In the absence of the added water, the lime-cashew nutshellliquid mixture may solidify before the lime can be thoroughly dispersedtherein and the hardness of the product makes the emptying of theapparatus inf.

which it is mixed more diificult. When an emulsion is reacted with theoxide or hydroxide, it is advantageously heated to a temperature above50 C.

The reaction between lime and cashew nut shell liquid of high anacardicacid content is exothermic, so that the mixture becomes hot and remainsfluid for a time and then sets on cooling.

While the mixture is in the fluid stage, it may After storage and/orshipment of the solid product, produced by the above-described reaction,the cashew nut shell liquid maybe recovered therefrom in approximatelyits original condition by removing the metal combined with the anacardicacid by reaction thereof with a dilute mineral acid, say a 5% or 10%sulphuric, hydro chloric, or phosphoric acid, or a'dilute organic acid,such as oxalic 'ortartaric. It is preferred to use an acid which willform a water-insoluble salt with the metal in the product. At roomtemperature, the reaction proceeds rapidly at the surface of the solid,but the released liquid promptly forms a coating over the unreactedresidue, which stops the progress of the reaction. Thisstoppage can beprevented by raising the temperature of the mixture to about 50 C. toabout 70 C. and agitating vigorously to break the oil film, or by addingto the mixture a solvent for'cashew nut shell liquid, preferably onewhich is immiscible with water, such as hexane, ben zene, carbontetrachloride, trimethylethane, or

chloroform. The original orrecoveredcashew' nutshell liquid may alsobeused as a solvent for this purpose. The first procedure, namely, theone employing vigorous agitation-without solvent, exposes the unreactedparticles by'emulsifying the liberated cashew nut shell liquid,

, the necessity of obtaining completeremoval ofthe-lime and ofminimizingthe size of equipment required. The purpose of theseprecautions is to avoid the well known polymerization anddecarboxylation of cashew nut shell liquid. The product so treated, thatis the entire reaction mixture, contains cashew nut shell liquid, diluteacid, with a calcium salt, which is soluble or insoluble, depending onthe. acid employed. These constituents may be separated in any suitablemanner, as by centrifuging, filtering, or decantation.

The following specific examples will serve to illustrate and explainthepresent invention, and

more particularly the formation of the limecashew nutshell liquidreaction product and the subsequent recovery of cashew nut shell liquidtherefrom.

Example 1 grams of slaked lime (Ca(OH) 2) is placed in asuitablereceptacle and is reacted with 300 grams of cashew nut shell liquid,having an anacardic acid content of approximately by adding of thecashew liquid to it in several portions, each of which is stirred invigorously until a smooth paste has been formed. Then the remainder ofthe cashew nut shell liquid is added and incorporated into, the paste.Considerable heat is evolved in the preliminary step of the reaction.The final mass remains soft for a-time and then gradually hardens as itcools to room temperature. This transition continues after the mass hascooled. During the soft sta e, the mass can be transferred to suitablecontainers and made to conform to their shape by the application ofpressure thereto. The final product has about the texture and hardnessof a chilled chocolate liquor, and like the latter, can be readilychipped or grated, or otherwise comminuted.

, Example 2 I 22 grams of slaked lime (Ca(OI-I) 2) is reacted with 200grams of cashew nut shell liquid'having an anacardic acid content ofapproximately 65% in the manner described above in Example 1, exceptthatthe reaction was somewhat accelerated by warming the plastic mass toa temperature of about 65 C. to C. While still warm, the mass fiowsunder its own weight and when poured into a bag will automaticallyconform to its shape. In fact, the product retains a considerable degreeof plasticity during its storage.

Ratios of the reactants intermediatedbetween those of Examples 1 and 2will giveproducts with intermediate properties. 1

Example 3 Recovery of cashew nut shell liquid from the solidifiedproduct.

140 grams of solidified eashewnut shell liquid containing 20% of addedCa(OH)2 were reduced to shavings, covered with 250 cubic centimeters ofwater and agitated with a motor driven stirrer. 40 grams of sulphuricacid diluted with cubic centimeters of Water were slowly added to thesubdivided material. The temperature of the material was slowly raisedto 65 C.-70 C. and after 2 hours, the resultant emulsion was broken bysuction filtration. separated and washed repeatedly with warm wateruntil excess acid had been removed. The recovered oil was then driedover anhydrous sodium sulphate. V

The procedure for using a solvent, such as those previously mentioned,is similar, and the solution is separated from the insoluble material.Subsequently, the dried solution 'must be distilled to remove thesolvent. When the reaction is "carried out on a commercial scale,regenerated The supernatant oil was cashew nut; shelllliquid mayibemsedas/a' solvent and .at-stheendof .each lcycle, .an ;.appropriate'quantity removed; frompthe system ;in....accordance with wellestablishedj'engineering principles.

Example 4 proXiin t Lv 60 :1 t tr .ei-the moisture. o teoftheliqllidhpito 'PBIQBH. liqu d. is then .heatedtoa tempe-.. .tof --wih.. u

ficient stirring to. disperse the ater thoroughly in the liquid andtodorm-a mate. in-oilem s q An amountofslakedli ie ual :s yen en e centvof the wei ht of; Fluid t nz ed the. emulsion; andmthe atter. Themixin.iseontinued iorrfive minutes, durin .Which the temperatur rises. isabnu 9010. and the plastic..material .isz.then poured into mold t0 COOL1.. .j. l

;.The amount of: slaked Ln. e..-1 sedin; theabove examp e is. one red ae tyrer e tin cessof. the amoun the re. ally n cess ry r .act .to. formth -.neutra sa t .th theanacetd acid .of the, liquid, assuming ha thslaked-lime is n n t -.Qn sper ntc um cashew .nut shell. qllld.. iXyi'fp l'fiel 115? cardic. acid. ;.'I?he...amou5nt; ofe im fid 9l 1 bevaried. iniaccordance with the ca cium hydroxide contentqfithe and, heaci., o ,tent'of the oil. q

. It will h notedin;th .;;abore. xamp ztha afterethe- Water was .added.t theca hew nut shell liquid, the latter was heated co 69 C. 5 It hasbeen tound. th t at temp ra be ow, ,.50..c.,.the..greater.yiscosityloithefliqui in ibits. t dispersion .oflime. therein and: 5116.133 1219. tweenthe-.in r d ents isslo and often.ns mplete.-

' Elmo wk. 5 l

In the-following example, a methodof 'regencrating anacardic acid fromthe plastic-product herein described by'the' use ofox-alic- 'aci'dand'an organic solvent is described."

A mixture of llli grams of -c-alci -um-hydroxide and 1650 grams of anemulsion --of;cashew nut shell liquid are-prepared-according to themethod described in Example 4. Whencool,--this;product is leached atroom temperature withacetone un- "til practically free'from solublematerial. The acetone-wet solid is treated with a solution --of 205grams of oxalic 'acid-in-one liter ofacetone and -the mixture isstirredfor one hour while it is heated to a temperature just below its looilingpoint. The solution is then filtered and theresidue' is washed withtwoportions-of "200 cubic centimeterseach of acetone, "The filtrate isthen -a concentrated by distillation and the-final traces.

of acetone are removed under-vacuum. *The-resulting'liquid. uponcooling; precipitates a small amount, of crystalline oxalicacid whichmay-be removed by ;filtration. Theyield of -anacard-ic acid is'317grams, 91.7% pure; which is 74% of theory; "Iheprocess results in theseparationof omponents of the cashew nut shell the phenolic c 7 liquidfrom the anacardic acid, and this--method .of regenerating the anacardicacid plastic product is not claimed' specifically herein since 'theprocess of separating the phenolic components from anacardic acid is thesubject matten ofcopending: applicatiomSerial No. 53.3 409 fi edAPri129,1-944. 4.1.;

hydrq ideand the Cir anesthesia.-e.

:l/Vhile the-above examplesdeseribed theuse of s1aked-lim .;uns1akedlime. may a s be em loyed, but the reaction of limewith cashew nut shellliquid of high anacardic acid content is more rapidly :efiectediwithslaked lime, the use of which gis therefore, preferred. The lime.undoubtedly reactswith the .anacardic acid of the liquid andmay alsoreact with other constituents of the liquid, although this is notdefinitelyknown. Thejlime must be used suliicient amountto produ e a pasti product in which th ana ard acid is stabilizedagainst decompositionas a, result of 'its conversionat least in part into one or. more ofitsealeiu salts The od orme is a :rn-aterial from which cashew nut shellliquid can .be readily liberated and which will not undergodecomposition during storage and shipment thereof. However, theplasticity of the reaction product decreases with an increasing amountof lime.

Generally, with cashew nut shell liquid h'aving from 40% to 70%an-acardic acid content, it is essential, touse an excess of thetheoretical quantity of lime based upon that required to react with theanacardic acid to form a" neutral salt thereof. Also, as the an-acardicacid content of the cashew nut shell liquid increases, the

degreeiof plasticitydecreases.

. Anacardic acid -has the following structural formula: 11

0 n-o ocoon u H.O O l5 2l 0 I .H I in which the Ciel-I27 is anopen,unsaturated hydrocarbon chain containing two double bonds 1 (i. e., fourunsaturated carbon atoms). The decarboxylation of anacardic racid (i.e., thelgss-of CO2 from its contained carboxyl group) yields thefollowing phenol known as anacardol:

:This phenol is. probably present in some proporinto anacardol bytheihigh temperaturetreat- I ment employed for'extraetion. Accordin tothe literature, the percentage of-anacard-icacid in-.heat-.extracted-oils is. not substantially-greater than 16%, forexample, see the article by Harvey and C'aplari in Industrial andilngineering amicable to .-.cashew nutshel lio i l cardic..;aei ip.r.es

. Chemistry}! October, 1940, Cashew @nut shell liquid, pages 1-306to1310'.

On the other hand, the oils which may nowbeobtained bythe simple methodof pressureextraction are known to con- :tain asmuch as. {705% anacardicacid,

. It is. to .be understood that :the inyention is apd. h ving-anas -thenin. P port on gr at anacardic acid show that the solid reaction productof the present invention requires the use of cashew nut shell liquidhaving an anacardic acid content of at least 40%. The reaction productsobtained with cashew nut shell liquids containing less than thispercentage of anacardic acid are free-flowing masses incapable of beingpacked in paper containers.

Anacardic acid is theoretically capable of producing the followingcalcium salts by reaction with one or two equivalents of alkali:

(1) Neutral salt(C22Ha1O3) 202 All three of these anacardates may bepresent in the reaction product with lime.

It is not an object to prepare any of these salts as such, but to keepthem in contact with the remainder of the cashew nut shell liquidconstituents in order to confer desirable properties on the mixture.There appears to be a marked degree of mutual solubility between theproducts formed since in a properly formed mixture, unreacted specs of'lime are the only evident signs of lack of homogeneity.

The plastic character of the reaction product of the present inventionwhich adapts'it for storage and shipment is an important advantage. Forexample, the plastic product is unlikely to poison persons coming incontact with it because of its inability to enter the pores of the skin.Moreover, it may be stored and shipped in ordinary paper bags or otherinexpensive containers without decomposition or loss of constituents bybleeding. It may be shipped in metal containers, in which case alleffects of corrosion formerly produced by storage and shipment inmetallic tamination of the product with foreign matter. While theinvention has been described in detail with specificexamples, suchexamples are illustrative and are not given as limitations, since othermodifications within the spirit and scope of the invention will beapparent to those skilled in the art. Hence, the invention is to beunderstood as limited only as indicated in the appended claims, in whichthe intent is to set forth all the novelty over the prior art.

I claim as my invention: r

l. The method of'converting cashew nut shell liquid containing'the usualnon-acidic constituents of cashew nut shell liquid and having ananacardic acid content of from'at least 40% to. about 70% into ahardened plastic product capable of being stored and shipped withoutsubstantial loss thereof due to decomposition or loss of constituents bybleeding which comprises mixing and reacting said cashew nut shellliquid with an alkaline earth metal compound selected from the groupconsisting of 'an oxide and a hydroxide in an amount in excess of thattheoretically required to form a neutral alkaline earth metal salt ofthe anacardic acid content of said liquid, forming "and hardening theproduct of said reaction into-a hardened plastic product of sufficientbulk to prevent appreciable air-oxidation of the product, said productbeing capable of regenerating cashew nutshell liquid in substantiallyunoxidized condition upon treatment of said roduct with an acid capableof forming a salt with the alkaline earth metal ofthe product.

2. The method of claim 1 wherein the alkaline earth metal-compound' is acalcium compound selected from the groupconsisting of slaked andunslacked lime.

3. The method of claim 1 wherein the cashew nut shell liquid treated.has an anacardic acid content'of from 50% to 70% and wherein thealkaline earth metalcompound is a calcium compound selected from thegroup consisting of slaked and unslaked lime and is present from about12% to about 25% by weight of the cashew nut shell liquid.

4. The methodof converting cashew nut shell liquid'containing the usualnon-acidic constituents of cashew nut shell liquid and having ananacardic acid content of from at least 40% to about'70% into a hardenedplastic product capable of being stored and shipped Without substantialloss thereof due to decomposition or loss of cnstituents by bleedingWhichcomprises forming a water-in-oil emulsion ofsaid cashew nut shellliquid, mixing and reacting said emulsion with analkaline earth metalcompound selected from the group consisting of an oxideand a hydroxidein an amount in excess of that theoretically required to form a neutralalkaline earth metal salt of the anacardic acid content of said .liquid,forming and hardening the product of said reaction into a hardenedplastic product of sufficient bulk to prevent appreciable air-oxidationof the product, said product being capable of regenerating cashew nutshell liquid in substantially unoxidized condition upon treatment ofsaid product with an acid capable of forming a salt with the alkalineearth metal of the product. I

5. The method of claim 4 wherein the cashew nut shell liquid treated hasan anacardic acid content of from 50% to 70%, wherein the alkaline earthmetal compound is a calcium compound selected from the group. consistingof containers are eliminated, thus preventing con-- 7 slaked andunslaked' lime andis' present from about 12% to about 25% by weight ofthe cashew nut shell liquid, and wherein the reaction is con ductedat atemperature of at least 50 C.

6. A hardened plastic product of sufiicient bulk to prevent appreciableair oxidation thereof and capable of being stored and shipped withoutsubstantial loss thereof due to decomposition or loss of constituents bybleeding comprising the reac- I tion product of cashew nut shell liquidcontaining the usual non-acidic constituents of cashew nut shell liquidand having an anacardic acid content'of from at least 40% to about andan.

alkaline earth metal compound selected from the 'group consisting of anoxide and a hydroxidein an amount in excess of that theoreticallyrequired content of said liquid, said product being capable ofregenerating cashewnut shell liquid in sub- .7 stantially unoxidizedcondition'upon treatment product. 7

of said product with an acidcapable of forming a salt with the alkalineearthmetal of the 10. The product of claim9 wherein the cashew .nutshell liquid treated has an anacardic acid content of from 50% to 70%and wherein the alkaline earth metal compound'is a calcium compoundselected from the group consisting of slaked and. unslaked lime and ispresent from about 12% to about by weight of the cashew to form theneutral alkaline earth metal salt of I 7. The product of claim 6 whereinthe alkaline earth metal compound is a calcium compound selected fromthe group consisting of slaked and unslaked lime.

8. The product of claim 6 wherein the cashew nut shell liquid treatedhas an anacardic acid content of from 50% to 70% and wherein thealkaline earth metal compound is a calcium compound selected from thegroupconsistingof slaked and unslaked lime and'is present from about 12%to about 25% by weight of the cashew nut shell liquid. r

9. A hardened plastic product of sufiicient bulk to prevent appreciableair oxidation thereof and capable of being stored and shipped withoutsubstantial loss thereof due to decomposition or loss of constituents bybleeding comprising the reaction product of a water-in-oil emulsion ofcashew nut shell liquid containing the usual non-acidic constituents ofcashew nut shell liquid and having an anacardic acid content of from atleast 40% to about 70% and an alkaline earth metal compound selectedfrom the group consisting of an oxide and a hydroxide in an amount inexcess of that theoretically required to form the neutral alkaline earthmetal salt of the anacardic acid nut shell liquid.

11. The method of converting cashew nut shell liquid containing theusual non-acidic constitue ents of cashew nut shell liquid and having ananacardic acid content of from at least 40% to about into a hardenedplastic product capable of being stored and shipped without substantialloss thereof due to decomposition or loss of constituents by bleedingwhich comprises mixing and reacting said cashew nut shell liquid with analkaline earth metal compound selected from the group consisting of anoxide and a hydroxide in an amount in excess of that theoreticallyrequired to form a neutral alkaline earth metal salt of the anacardicacid content of said liquid, forming and hardening the product of saidreaction into a hardened plastic product of sufiicient bulk to preventappreciable air-oxidation of the prod not, said product being capable ofstorage and shipment without substantial loss thereof and ofregenerating cashew nut shell'liquid in substantially unoxidizedcondition upon treatment of said product with an acid capable of forminga salt with the alkaline .earth metal of the product, andafter shipmentor storage subdividing said hardened plastic product and recovering thecashew nut shell liquid content thereof by treating thev subdividedmaterial with an aqueous'solution of an acid capable of forming asalt'with the alkaline earth metal of the product. 12. The process ofclaim '11 wherein the alkaline. earth metalcompound isa calcium compoundselected from the group consisting of slaked and unslaked lime.

. ROLAND E. KREMERS.

